While power lines seem like mundane structures to us, researchers have come up with a new explanation about why animals are avoiding them.
Scientists have noted in the past that animals in varied habitats avoid power lines, even long after they’re built, but weren’t sure exactly why because they’re easy to pass by and aren’t associated with people. One explanation was that they avoided the open areas that were cleared to build power lines because they would make them vulnerable to predators. However, this theory wouldn’t apply to a species like reindeer who live in open tundra.
Now a team of researchers from the University College London (UCL), Moorfields Eye Hospital, London, UIT The Arctic University of Norway and the University of Oslo in Norway believe they have come up with the answer and that UV light is the culprit. Their findings were published in the journal Conservation Biology.
High-voltage power lines emit flashes of UV light when buildups of ionized gas are released at insulators and points along cables. While these flashes are invisible to the human eye, a number of species can see them. Now researchers believe animals are seeing power lines as flashing streaks of light cutting across the landscape.
While it’s been known that birds, fish, and some reptiles and amphibians were sensitive to UV light, another recent study found that a variety of mammals, including dogs and cats, can see some level of UV light. Reindeer, who have adapted to survive the dark Arctic winters, are particularly sensitive to it.
“New information about animal vision along with the characteristics of power lines provides strong evidence that the avoidance may be linked with animals’ ability to detect ultraviolet flashing on power lines that humans cannot see and which they find frightening,” said Professor Glen Jeffery, UCL Institute of Ophthalmology, in a statement.
Researchers now believe these flashes are making power lines appear as scary looking lines that are impacting wildlife around the world by altering migration routes, fragmenting habitats and cutting off access to grazing land, which is a theory that would be particularly applicable to reindeer.
“The loss and fragmentation of habitat by infrastructure is the principle global threat to biodiversity – it is absolutely major. Roads have always got particular attention but this will push power lines right up the list of offenders,” Dr. Nicolas Tyler, an ecologist at UIT The Arctic University of Norway, told the Guardian.
Not only are these sparks bad for wildlife, but they’re also a sign of inefficiency and are early indicators of problems. Power companies use helicopter-mounted cameras to try to find them and fix issues, but won’t be able to eliminate them entirely. According to Jeffrey, even with our ability to see what the UV cameras pick up, it’s still only a glimpse of what animals see.
Researchers hope that this discovery will at least help with future decisions about where power lines are placed. According to the Guardian there is a plan to build a 186 mile power line through Norway, and they hope their work will encourage power companies to work with reindeer herders on its placement.
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